Nature World: For the first time, carbon dioxide (CO2) levels have reached a record-breaking milestone, its monthly concentrations topping 400 parts per million (ppm) in April throughout the Northern Hemisphere, the World Meteorological Organization (WMO) reports. (Photo : Reuters/Yves Herman)
For the first time, carbon dioxide (CO2) levels have reached a record-breaking milestone, its monthly concentrations topping 400 parts per million (ppm) in April throughout the Northern Hemisphere, the World Meteorological...